SUPERMAN RETURNS had one flying man, some large sets that can be compared to the kinds of sprawling, futuristic sets we're talking about, Braniac's ship, etc, etc, and decent sized action. It cost what, $200 million?
I think $150-160 million for a movie with 7, 8, 9 flying people with various superpowers, one of whom is Superman (who has multiple powers and has to do several feats), some which are very visual, and any kind of big action is wishful thinking at best.
I like Superman Returns, but one of the many problems I had with it was the horrible ways they spent their money. But, technically they spent $200 million on a THREE hour movie and not a two and a half like the one we got. So maybe they didn't spend their money too bad, but I guess we'll never know.
As for multiple people flying that Peter Pan movie from 2003 had a crap load of people flying and insane amounts of Cgi for neverland. That movie cost less than $100 million. Also, Green Lantern is going to have all the stuff you described and I think it has a budget of $150 million.
Now I'm not saying this movie should be like Peter Pan (it was a beautiful movie though), I'm just saying it's possible. But like I said this movie would no doubt have to be less than 2 hours long to keep the price down.